The present invention relates to the novel derivatives of tetrahydrobenzothiazolyl-1,3,5-triazinone, represented by the formula(I): ##STR4## wherein R represents a chemical group selected from the group consisting of 1-phenylethyl, 1-methylpropyl, 2-methylpropyl, allyl, 2-propynyl, cyclopropyl, cyclopentyl, phenyl, ethoxycarbonylmethyl, 2-tetrahydrofurylmethyl, 2-acetoxyethyl, 2-chloroethyl, 2-cyanoethyl, 2-hydroxyethyl, 2-methoxyethyl, 2,2-dimethoxyethyl, 2-(propionyloxy)ethyl, 2-(ethoxycarbonyl)ethyl, 2-(4-chlorobenzoyloxy)ethyl, 1-(hydroxymethyl)propyl, 3-hydroxypropyl, 3-methoxypropyl, 3-acetoxypropyl, 3-morpholinopropyl and 3-(2-methylpiperidino)propyl.
As a result of the present inventors' studies concerning novel compounds showing favorable herbicidal activity, they have found that the novel derivatives of tetrahydrobenzothiazolyl-1,3,5-triazinone show excellent practical herbicidal activity and have attained the present invention.